Etach is an Emacs add-on that allows easy management of MIME email
attachments in RMAIL and Mail modes. Attachments and detachments are
as simple as entering the Emacs commands M-x attach and M-x detach,
respectively. Also provided is the ability to forward mail via
message/rfc822 format (M-x mime-forward), useful when forwarding
messages that contain MIME attachments.

Log message:
Move mk/emacs.mk to editors/emacs/modules.mk.
Don't call pkg_info to get the installed Emacs version; always use the
version matching EMACS_TYPE set by users. Be DEPENDS to it. This should
address pkg/37146 by Aleksey Cheusov.
While here convert some emacs lisp packages to user-destdir.